[MOC] Telehandler

Recommended Posts

Everyone and their grandma have built a telehandler model, and here's my take on the subject.

This is my most complicated model yet, and the development history started back in January, 2013. This model was always the too-complicated one that was cast aside for other models (mainly much simpler cars).

The functions are powered with three L-motors, two of which are powering the elevation.

There is a gearbox for two operation modes: boom elevation+extension and outriggers+fork elevation.

The functions can be operated with two PF pole reversers.

The model went through some complete start-overs, and the final build started at the beginning of May. Everything was restarted from scratch except for the overall look, the boom and part of the gearbox.

The main booster of the final building course was the introduction of the new Claas model, which didn't have a fake engine and driveline. This encouraged me to make this trade-off too (it's good enough for TLG too, and a fake driveline isn't really adding anything to playability). This saved a lot of space and making the axles sturdy became much simpler.

Another booster was relocating the L-motors above the front axle, which also gave a lot of space. The model became quite lightly packed and tidy.

Luckily, Barman also posted his idea how the steering in the Claas model is probably built, and I could incorporate and improve his design. I had another system too, but that sometimes jammed because of the knob gears it used.

I improved Barman's initial design by adding a carriage for the link between the front and rear linkage. The rear part is also operated by a carriage, so the whole steering linkage is only 2 studs high. And also everything is doubled to reduce backlash. The system works surprisingly well.

The fork leveling is simply solved by connecting the fork drivetrain and the boom elevation drivetrain with a proper gear ratio. The leveling is always driven by the motors. This also means that the boom elevation and the fork angle can be independently moved in only two gearbox states. This doesn't reduce playability, since due to the auto leveling, one hardly has to adjust the fork angle.

The maximum angle and length of the boom is quite limited (the above picture shows the maximum angle and length), probably the motors and linear actuators could handle a bit more, but this would require quite some redesign (gearbox for proper auto-levelling, mounting points of the LA, etc).

The model is built from about 2100 parts.

Video will be ready in a few weeks (or months) and the steering will be explained in detail.

Share this post

Link to post

Share on other sites

Fantastic looks and colour scheme. I really am looking forward to see the steering mechanism. Oh, and I must urge my grandma to start building one asap. Seems that me and her are one of the last people who haven't build a telehandler yet :-)

Share this post

Link to post

Share on other sites

Is this the largest telehandler we've seen? I love it. I would have liked to see some yellow colouring (sides and back) but that's minor. The model looks good, the functions are good and it's quite a size.

Share this post

Link to post

Share on other sites

The LDD file is almost ready but I'm not sure about making proper instructions. The last one I made was very hard and time consuming to make.

The boom look pretty robust. Did you try lifting some weights with that?

Weightlifting was not a main concern, but I tried it now. With almost fresh batteries it's able to lift a full battery box (the one with the 6 AA batteries). Though the LAs clicked sometimes. When I tried lowering the boom (to check if the auto-leveling can keep up, and it could), uneven occasional clicks in the big LA's caused slight desynchronization and higher stress. So I guess it's not safe to lift the bigger battery box.

Without load, it can easily lift the fully extended boom.

I'd say it is able to reliably lift a brick built cargo, I will build a pallet and some cargo for the video.